1. Field of the Invention
This invention relates to a catalyst for hydrodesulfurization of mineral oils. More particularly, this invention relates to a catalyst comprising Group VIB and Group VIII metal components composited with an alumina support prepared by a specified method.
2. Description of the Prior Art
Hydrodesulfurization processes in which heavy hydrocarbon oils or residual oils are treated with hydrogen in the presence of a catalyst comprising a hydrogenation component composited with a refractory oxide support, such as alumina, are well-known.
It is known to prepare a zirconia-coated alumina and thereafter to impregnate the coated alumina with a solution of the desired active metal to produce catalysts or sorbents. See U.S. Pat. No. Re. 29,771.
A hydrodesulfurization catalyst is also known which comprises a non-zeolitic refractory oxide carrier, Group VIB and Group VIII hydrogenation components and a Group IVB metal oxide, which may be zirconia. See U.S. Pat. No. 3,840,473.
It is known to prepare a porous catalyst carrier by treating a powdered solid comprised of predominantly alpha alumina monohydrate with a monobasic acid, followed by neutralization with a base such as ammonia, drying and calcining. See U.S. Pat. No. 4,082,697. The use of acid-treated boehmite as binder in siliceous catalysts is known. See U.S. Pat. No. 3,652,449.
It has now been found that a catalyst prepared by a specified method has advantages that will become apparent in the ensuing description.